Choosing the correct CPU?

[AlrightDave!]

Hi all,

I am a noob here and would appreciate some advice from this excellent community. I have previously used the benchmarks to help decide on a good PC setup, but now I am second-guessing myself. I am building a PC for Poker Solver projects. The software is written for multi-threaded CPUs, but I receive contradictory advice when asking other players and PC builders. Even the software designers give different advice! Some are saying the clock speed is less important than the number of cores/threads. Others say it is the number of cores and the threads are irrelevant. Then I am told it is a combination of clock speed multiplied by the number of cores. I asked if 20cores 40 threads at 2.5Ghz are better than 16core 32threads at 3.6Ghz, and the replies were 50/50!

I have found myself so confused as their answers don't appear to share a common thread; please forgive the pun!

I was considering a Ryzen 9 5900X; it has the highest Passmark score within my budget.

What is the best way to determine the best CPU when the software is CPU intensive?

I am sorry if this is a stupid question; I am now bewildered.

TIA

[David (PassMark)]

I am building a PC for Poker Solver projects

This is really the key.
Each bit of software is slightly different. So the question is impossible to answer accurately without knowing the exact software and version being used and how it has been coded (in detail).
If you don't have this information, then something like the Ryzen 9 5900X would be an excellent all round CPU. Would be hard to go too far wrong with this CPU.

[AlrightDave!]

This is really the key.
Each bit of software is slightly different. So the question is impossible to answer accurately without knowing the exact software and version being used and how it has been coded (in detail).
If you don't have this information, then something like the Ryzen 9 5900X would be an excellent all round CPU. Would be hard to go too far wrong with this CPU.

Hi David

Thank you for taking the time to reply; you have hit the nail on the head. I have asked the software vendors for this information, but their replies are woolly honest. One said the 5900X would "probably be better" because balancing the threads on the Xeon Dual CPU may be an issue; whatever that means?

Another vendor was more forthcoming and said "the higher number of threads" would be their preference. The other vendor did not afford me the courtesy of a reply. Both vendors say their code is optimised for as many threads as you can provide. I have a colleague running an AMD Ryzen Threadripper PRO 3995WX, and he says it engages all the threads if he allows it. I don't have his budget, though!

Someone else suggested it was a simple formula (Cores x GHz), then someone else chimed in with (Core x Iterations per clock) - this was on a Poker coaching group Zoom meeting.

I am definitely confused!

Many thanks

Dave

[David (PassMark)]

The only way to really know is to run these exact software packages (same software & version of the software) on a few different machines and see what the throughput is and see how it scales as you add cores. Sounds like the vendors haven't done this. Which isn't totally surprising as performance optimisation is a secondary consideration for most developers.